The present application generally relates to hot fluid fryers for the continuous hot fluid frying of large quantities of food products, particularly for large scale food process lines. More specifically, the application is directed to a frying system having a housing with a tank portion that holds a bath of cooking oil with an endless conveyor system attached to the housing for conveying a food product through heated cooking fluid, such as oil or the like.
Frying systems have evolved significantly over the past 30 years. The need to process greater volumes of food product has caused the size of frying systems to increase. Some flying systems now measure 30 feet in length and 60 inches in width. Of course, a larger frying system means larger volumes of cooking oil are necessary to operate these systems. However, oil prices have also increased over time, thus oil used in frying systems is increasingly expensive. For example, a 30 foot by 60 inch frying system requires 93 gallons of oil per inch of tank height. Accordingly, modern frying systems must not only meet today's high-volume processing demands, but must also meet today's low oil volume requirements.
The frying system of the present application includes a housing having a tank portion for holding the bath of hot cooking fluid. The housing may also include a hood portion located in a plane above the tank portion and covering the tank portion when in use. An endless conveyor system may be attached to the housing, the conveyor system comprising a submerging conveyor, a main conveyor and a sediment conveyor. The conveyor system is adapted to carry product portions on an upper run of the main conveyor from an in-feed end of the housing to a discharge end of the housing. The submerging conveyor is arranged above the main conveyor and operates to hold the product on the upper run of the main conveyor. The main conveyor and submerging conveyor operate together to pass product through the bath of hot cooking fluid when in use. The runs of the submerging conveyor and the main conveyor through the bath of hot cooking fluid define a cook zone where the product is cooked. The sediment conveyor is located below the main conveyor and operates to remove debris from the bottom portion of the tank. A drive system operates to drive the conveyor system to accomplish the functions described above.
A heat exchanger is continuously connected to the frame of the sediment conveyor. The heat exchanger is operable to heat the bath of cooking fluid, such as oil or the like, and is, therefore, adapted for submergence into the bath. The heat exchanger of the present application includes a plurality of elliptical shaped heating conduits, each conduit having an inlet end attached to an inlet manifold and an outlet end attached to an outlet manifold for circulating heated fluid through the heat exchanger to accomplish heating of the hot cooking fluid bath. The plurality of elliptical shaped heating conduits are arranged horizontally across the tank portion of the housing and may be mounted in the direction of product flow. Each of the plurality of elliptical shaped conduits comprise a baffle. The baffle may operate as a fluid flow optimization member for redirecting the flow of fluid. The redirection of heating fluid may be in a helical path. The baffles comprise an elongated insert running longitudinally through the elliptical shaped conduit channel. In some embodiments, the baffles bisect the conduit channel. In one embodiment, the baffle comprises a plurality of orifices and a plurality of vanes. The orifices may be turbulence inducing orifices. The orifices and vanes, either together or separably, operate to create an internal swept surface heat transfer condition within the conduit channel. The conveyor system and heat exchanger together provide a low-profile design, minimizing the amount of cooking oil necessary for use.
The frying system of the present application also includes a power source co-acting with the housing for lifting the hood portion of the housing upwardly. The hood portion, the submerging conveyor, the main conveyor and the sediment conveyor are successively coupled such that when the power source is activated to lift the hood portion of the housing, the conveyor system can also be moved upwardly to an inoperative position above the bath. Specifically, when the hood portion of the housing is raised upwardly, the linkage between the hood portion and the submerging conveyor, the linkage between the submerging conveyor and the main conveyor, and the linkage between the main conveyor and the sediment conveyor will cause the consecutive elements of the conveyor system to be successively extracted from the bath. The power source operates such that the conveyor system may be partially removed from the bath, wherein the submerging conveyor and main conveyor are removed from the bath, while the sediment conveyor remains in the bath.
A PLC control may be used, in some embodiments, to provide control of the bath temperature, control of filtration, activation of the power source to raise and lower the hood and conveyor system, continuous monitoring of oil levels, dual zone temperature control of the bath and/or real time data feedback.